The popularity of hydrangeas in residential landscapes and gardens is evident in their widespread use for their large, colorful blooms. Modern gardening increasingly recognizes the environmental importance of supporting local ecosystems, making the question of a plant’s value to pollinators a primary concern. Whether a hydrangea provides sustenance for bees is not a simple yes or no answer, as its utility depends entirely on the specific variety planted. The choice between one cultivar and another can determine if the shrub acts as a food source or merely as a decoration in the garden.
Flower Structure and Pollinator Access
Hydrangea flowers are comprised of two distinct types of structures, which determines their usefulness to foraging insects. The plant produces large, showy florets that surround the flower head, acting as visual attractants to draw pollinators in from a distance. These outer florets are purely ornamental, lacking both the nectar and pollen that bees require for survival and colony health.
The true resource for bees lies in the smaller, less noticeable florets clustered in the center of the flower head. These tiny structures are the reproductive parts of the plant, containing the pollen and nectar that provide nutrition to visiting insects. When plant breeders select for the largest, most visually appealing blooms, they often inadvertently select for a higher proportion of the non-nutritive, showy florets. This selective breeding results in dense, snowball-like flower heads that offer little accessible food for bees.
This prioritization of appearance over function has dramatically reduced the pollinator value of many common hydrangea varieties. The tightly packed flower heads can physically obscure the small, food-producing florets, making them functionally inaccessible even if they are present. Consequently, many popular, hybridized hydrangeas are largely useless to bees, despite the insects being drawn in by the surrounding visual display.
Identifying the Best Hydrangea Species for Bees
Gardeners seeking to support bees should focus on varieties that maintain a high percentage of the small, fertile florets. The easiest way to identify these is by looking for the “lacecap” flower form, which features a flat cluster of the tiny, fertile flowers surrounded by a ring of the large, showy florelet advertisements. In contrast, the “mophead” form is dominated by the showy florets, offering minimal accessible pollen and nectar. In one study, lacecap flowers were visited by pollinators at three and a half times the rate of mophead flowers.
Several species are particularly good choices for maximizing pollinator benefit. Native North American species, such as the Smooth Hydrangea (Hydrangea arborescens) and the Oakleaf Hydrangea (Hydrangea quercifolia), are highly favored due to their open flower structure and adaptation to local insect populations. The Panicle Hydrangea (Hydrangea paniculata) also provides significant resources, especially in cultivars that retain a conical, open structure with accessible fertile flowers. Cultivars like ‘Annabelle’ and ‘Haas’ Halo’ provide abundant, open clusters of fertile flowers, ensuring the plant is a functional part of the local food web.
Ensuring a Safe Environment for Pollinators
The presence of fertile flowers is only half the equation; the plant must also be free of harmful contaminants to be a safe resource for bees. Systemic pesticides, particularly neonicotinoids, are a major hazard to pollinators and can be absorbed by the plant’s vascular system. Once absorbed, these chemicals are distributed throughout the plant’s tissues, meaning they can be present in the pollen and nectar that bees consume.
Neonicotinoid exposure, even at low levels, can impair a bee’s central nervous system, leading to disorientation, reduced foraging efficiency, and decreased reproductive success in queen bumblebees. Since these chemicals can persist in the soil and be continually taken up by the plant for long periods, it is important to purchase plants that have not been treated with them. Gardeners should avoid applying any soil drenches or granular products containing active ingredients like imidacloprid or dinotefuran to their hydrangeas.
A safe environment also includes providing supplementary resources to ensure a diverse and continuous food supply. Offering a shallow water source, such as a bird bath filled with pebbles for safe landing, supports the hydration needs of foraging bees. Companion planting with other high-value pollinator plants, especially those with staggered bloom times, helps maintain a steady flow of nectar and pollen throughout the growing season.